On graphs in which neighborhoods of vertices are isomorphic to the Higman-Sims graph

Abstract

The Higman-Sims graph is the unique strongly regular graph with parameters (100, 22, 0, 6). In this paper, amply regular graphs in which neighborhoods of vertices are isomorphic to the Higman-Sims graph are classified. This result continues the investigation of amply regular locally F-graphs, where F is the class of strongly regular graphs without triangles. © 2012 Pleiades Publishing, Ltd.